This invention is directed to a heat-resistant peroxide curable chlorosulfonated polyethylene or chlorinated polyethylene composition.
Both chlorosulfonated polyethylene and chlorinated polyethylene have been found to be especially useful as wire and cable coverings because of their resistance to ozone, oxidizing chemicals, heat and light. When these elastomers are used for wire and cable covering, generally, they are vulcanized by means of a conventional metal oxide-sulfur (or a compound that releases sulfur upon heating) curing system. A sulfur cure is used because sulfur imparts stable electrical properties to the elastomer. However, sulfur curing systems cause discoloration of the chlorinated polyethylene elastomer and, therefore, it has not been possible to obtain with a sulfur curing system an elastomer for wire covering that can be readily color coded for identification. The present invention provides a heat-stable, peroxide curable elastomeric composition that can be colored for identification.